A Sure Sign of Old Eyes

bearandoldman · Post by **bearandoldman** » Mon Sep 06, 2010 10:21 am

Hakaman wrote:
or find a way to raise the rear sight down.
you might try to lower the front sight little higher?
I think that would work !

Don't know why it wouldn't.

Post by **Bullseye** » Mon Sep 06, 2010 10:51 am

Greener wrote:I shoot at 15 yards about 75% of the time.

I wanted to see if this was worth the effort to file the top of the rear sight blade down a little. Since you use this distance the majority of the time it sounds like it would be beneficial. There's a formula for calculating the amount of correction on the blade, Brownells has a reference to it on their website Brownells

Sight change = (Sight Radius X Impact distance)/Target distance

The key to use this formula it to convert all your measurements to the same units of measure. In this case you'd want to use everything in inches. You won't have to remove very much material since you're really just wanting to move the point of impact only a few inches at fifteen yards (540"). So as a rough estimate, let's say you want to move your point of impact down three inches at 15 yards. That equates to approximately 7" of sight blade radius times three inches impact movement all divided by 540 inches of target distance. The amount of movement is downward, meaning removing material from the rear sight, that amount would be 0.039" off of the rear blade height. Apply some cold blue paste on the exposed edge of he blade where you filed and the job is done.

Hope this helps.

R,
Bullseye

greener · Post by **greener** » Mon Sep 06, 2010 5:12 pm

Thanks. I think I'll put the rear sight half-way up and take some tools and a calculator to the range. I probably ought to shoot off a rest.

Nice trip for sights. The 1911 shot low. The SR9 sights loosened and bounced left (POI ~ 5" left of POA). I didn't have the right allen wrench. The Hunter rear sight screw was loose. One whack and some blade centering and I fixed that.

Decided it was time to quit checking for loose screws this weekend.

bearandoldman · Post by **bearandoldman** » Mon Sep 06, 2010 5:51 pm

greener wrote:
Decided it was time to quit checking for loose screws this weekend.

Yours or the guns?

Post by **Bullseye** » Mon Sep 06, 2010 6:00 pm

Your point of impact will rise at mid-range so that will affect the amount of material that will need to come off the rear blade.

R,
Bullseye

greener · Post by **greener** » Mon Sep 06, 2010 7:32 pm

bearandoldman wrote:
greener wrote:
Decided it was time to quit checking for loose screws this weekend.
Yours or the guns?

Yes

Jack D · Post by **Jack D** » Thu Jan 06, 2011 7:35 pm

Hakaman wrote:-------------------------------------------------------------------------------------
Next two pictures are of my Ruger BlackHawk Convertable 45cal that a local gun smith cut & inserted a HiViz "into" the front sight blade.

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Looks like my Tonly Lama's under that SA revolver.